Abstract
Patients (4) suffering from familial periodic paralysis with hypokalaemia (FPP) were subjected untreated to standardized induction of paralysis. The induction was repeated after pre-treatment with the .beta.-receptor blocker propranolol (Inderal). In 3 of the patients propranolol had no, or even a negative, effect on the development of paralysis or on the fall in serum K. In 1 patient a slight prophylactic gain was achieved. It was not possible to demonstrate any difference in the serum level of glucose or insulin during the induction of paralysis according to whether the patients were untreated or treated with propranolol. Short-lasting out-patient treatment of the patient who had apparently had some slight prophylactic benefit from propranolol had to be discontinued after 11 days because of an unusually severe and long-lasting attack. Propranolol has no major effect in the treatment of FPP, unlike its favorable effect in thyrotoxic familial periodic paralysis (TFPP).